Carboxymethyl chitosan-zinc coating for prevention of pin tract infection: An animal model

Pin tract infection is a common problem in orthopedic and traumatology surgery. The aim of this study was to investigate the efficacy of an implant coated with carboxymethyl chitosan-zinc (CMC-Zn²⁺) in prevention of pin tract infection.

Twenty-four male New Zealand White rabbits were randomized into two equal groups ( n = 12, uncoated and CMC-Zn²⁺). The implants were colonized with 1 × 10⁶ colony forming units of Staphylococcus aureus and inserted into the lateral right proximal tibia in each rabbit. In each group, at 2 and 4 weeks post-surgery, five and seven rabbits were killed, respectively, to harvest the soft tissues around the implant as well as the hard tissue for histological analysis. The bone cross-sectional view, X-ray, and micro-computed tomography (μCT) were performed.

The surgical sites in each animal were evaluated individually at both time points. No evident signs of infections were found in the CMC-Zn²⁺ group, while a high rate of infection was observed in the uncoated group where minor infections were 85.71% ( n = 12) and major infections 14.29% ( n = 12). The radiography, μCT, and histological analysis showed no evident signs of infection in both groups at 2 weeks post-surgery. However, at 4 weeks, signs of infection were found in all the animals in the uncoated group, whereas in the CMC-Zn²⁺ group, no infections were observed. The difference between the two groups was highly significant ( p = 0.00).

Our study showed that CMC-Zn²⁺-coated implants were effective in preventing pin tract infection.